This paper reports development of an automatic procedure for measuring and representing three-dimensional geometry of man-made sites from stereo reconnaissance photography. The ability to derive such information from remotely sensed data has application within both the military and intelligence communities. Studies of typical reconnaissance have shown that precise models can be extracted, but current methods are laborious, and rely heavily on operator insight. This work addresses development of an automatic and digital method. Attention is restricted to sites composed of planar surfaces (e.g. buildings). For an automatic stereo system, these sites present the severe problems of abrupt change in slopes and image occlusion. These features thoroughly disrupt application of traditional automatic stereo techniques, which have been developed to model rolling natural terrain. The system reported here represents an entirely new design, based on correlation but specifically structured to the problem features of planar surface sites. A demonstration is achieved, on reconnaissance imagery, of automatic stereo measurement of a building complex. This work is expected to form a basis for advanced work in both automated and computer aided stereo technique.